Night vision imaging (NVIS) systems provide improved vision and situational awareness in low ambient light conditions to a viewer such as an aircraft pilot. A night vision imaging system allows the pilot or operator to use night vision imaging goggles while flying the aircraft. Night vision imaging goggles are sensitive to light primarily in the red to near-infrared wavelengths, approximately 610 nanometers (nm) to 930 nm in the electromagnetic spectrum (the near-infrared spectrum). Night vision imaging goggles allow the pilot to view outside conditions in low light using light in the near-IR spectrum, allowing aircraft operation during nighttime conditions.
It is important to ensure that avionics display systems provided in an aircraft are compatible with the use of night vision imaging goggles. If the light from an avionics display is within the near-IR spectrum and therefore viewable by the night vision goggles, the light from the display can be seen reflecting off the aircraft canopy, degrading goggle performance and pilot vision. Incompatible lights make the outside scene less visible with the goggles. Additionally, changing illumination can affect visual acuity.
One method of controlling this problem is to apply a filter to any display to be used during NVIS operation. The filter substantially reduces the transmission of light having wavelengths in the near-IR spectrum. Using such a filter, an emissive display can be used during night vision operations.
To save space and increase viewability, NVIS filters should be conformal to the displays with which they are used. A non-planar or a flexible display, such as a display relying on emissive organic light-emitting diodes (OLEDs) or a panoramic rear projection display, requires a correspondingly flexible NVIS filter if the display is to be used in NVIS applications. Although there is a need for a flexible, robust NVIS filter that can be used with flexible or non-planar displays, such filters do not currently exist.
It is therefore an object of the invention to provide a flexible NVIS filter that may be used with flexible or non-planar display technologies.
It is also an object of the invention to provide a flexible NVIS filter that can be easily and efficiently manufactured.
A feature of the invention is a flexible NVIS filter having a UV-curable filtering material disposed between flexible substrates or films.
An advantage of the invention is a fully or partially flexible NVIS filter usable with non-planar or flexible display technologies.